GI development

Question 1

define mesentery

Answer 1

two sheets of visceral peritoneum (=serosa=simple squamous epithelium=mesothelium) with CT and fat in b/w. Carry vessels and nerves to organs. Develop from splanchnopleure

Question 2

origin of greater peritoneal sac and what it is

Answer 2

the proper abdominopelvic cavity. Forms when ventral mesentery of ventral midgut and hindgut breakdown (initially divide peritoneal into L and R halves)

Question 3

what organs develop in the mesogastrium? What is the mesogastrium later known as?

Answer 3

Dorsal-spleen, greater omentum, lesser peritoneal sac. Ventral-liver and gall bladder, lesser omentum

Question 4

significance of hepatoduodenal ligament? what does it contribute to?

Answer 4

contains portal triad and marks jxn of foregut and hindgut at mid-duodenum. Along, with hepatogastric ligament it makes up lesser omentum (ventral mesentery of foregut)

Question 5

Meckel’s diverticulum

Answer 5

persistence of yolk sac stalk off of ileum. Can also be a fistula and you get lumenal connection to umbilicus. Also can be cyst, fibrous cord or volvulus. Can get infected and mimic appendicits

Question 6

communication b/w greater and lesser sacs? where?

Answer 6

epiploic foramen of winslow under free edge of lesser omentum

Question 7

list three adhesions of mesenteries

Answer 7

gastrocolic, phrenicocolic (suspensory ligament of spleen), hepatocolic. All connect to transverse colon

Question 8

list fibrous cords

Answer 8

round ligaments (‘teres’) of liver and uterus, ovarian ligament

Question 9

define primary vs secondary retroperitoneal organs and give examples

Answer 9

Primary: develop outside peritoneal cavity (kidneys, adrenal glands, aorta, ICV, bladder, prostate, vagina, rectum). Secondary: start in mesenteries then adhere to body wall (pancreas, duodenum, ascending and descending colon).

Question 10

list the retroperitoneal structures

Answer 10

SAD PUCKER (Suprarenal gland, Ao and IVC, Dodenum (first part), Pancreas (except tail), Ureters, Colon (ascending and descending), Kidneys, Esophagus (lower 2/3), Rectum (lower 2/3)

Question 11

foregut gastroschisis is called___

Answer 11

ectopia cordis